Akademik Veri Yönetim Sistemi
INTERNATIONAL JOURNAL OF POWDER METALLURGY, cilt.39, sa.2, ss.53-62, 2003 (SCI-Expanded)
The characteristics of rapidly solidified AA 2014 aluminium alloy ribbons produced by a water cooled rotating disc have been investigated with respect to microstructures, cooling rates, shapes and surface morphologies. A new apparatus was used in which cooling was done from the opposite side of the disc so that the cooling water was not in contact with liquid metal. The effects of parameters such as cooling water temperature, disc material, disc rotation speed, superheat and flow rate of the liquid alloy on the sizes and microstructure of the ribbons were investigated. The as-produced ribbons were 25-200mum in thickness, 2-12mm in width and 30-80mm in length, and were crescent shaped. The thickness of the ribbons decreased with increasing desc speed, decreasing liquid metal flow rate and increasing melt superheat. The microstructure of the ribbons was characterized by three zones: a thin featureless zone on the disc side; a zone of relatively coarse cells in the middle part of the ribbon; a zone with relatively fine cells on the air side of the ribbon. Submicron size despersoids were observed in the cell boundries. The cooling rate of the ribbons produced by a copper disc was higher than that of stainless steel. Decreasing melt superheat and the temperature of the cooling water from 18degreesC to 0degreesC increased the cooling rate of the ribbons. Maximum cooling rates were estimated as 2.6x10(6)K/s and 1.6x10(6)K/s, produced by copper and stainless steel discs, respectively.